Separator and method of making the same



I Patented Apr. 10, 1928.

UNITED STATES.

PATENT OFFICE.

WILL IAM S. GOULD, Oil? NEW YORK, AND. WILLARD B, OSBORNE, OF ELMA, NEW YORK, ASSIGNORS TO GOULD STORAGE BATTERY COMPANY, INC., 01? NEW YORK, N. Y-, A

CORPORATION OF NEW YORK.

sErAnAroRANn METHOD or MAKING THE em.

No Drawing.

Our invention relates to storage battery separators and method of making the same. It has long been the desire of storage battery manufacturers to produce a battery with treated separators which can be shipped dry. The difliculty heretofore experlenced has been that if the treated separators were dried before placing in the battery they split or curl to such'an extent that they- We have devised a method of treating the separators whereby they may be completely 2 dried without any curling, cracking or s 11tting. By reason of this method, the attery elements may be'assembled dry'm the factory, shipped to their destination and the electrolyte supplied, thus avoiding the dangers and other difficulties 'of transporting a battery containing sulphuric acid electrolyte. Furthermore, the separators resultmg from our method may be stored by manufacturers and dealers in adry state, thus greatly simplifying the problem of carrying a stock of separators. It has heretofore been necessary to keep such, separators in large tanks where they could be kept wet until used.

white cedar in the form of boards or veneer are put into a solution of approximately 3% caustic soda at a temperature at approximately 212 F. for about eight hours. They are then removed from thissolution and placed in clear running water for about fourteen hours to remove the caustic soda. They are then put into a weak solution of sulphuric acid about 1.02 specific gravity to and left there a sufiicient timeto allow the that might remain in the wood after washing, usually about two hours. They'are then immersed in hot water for about two A suitable wood, such as Port Orford Application filed October 23, 1923. Serial No. 670,822.

hours which neutralizes the acid. They are then put through a drying machine of any desired construction but preferably. havin a series of movable steam-heated, horizonta iron plates, which rest against the "opposite surfaces of the boards or veneer and which won plates are heated sufliciently to rapidly dry the wood. The plates hold the wood 'flat while it is being dried and preferably are so arranged that thewood is held under" a slight pressure between the hot plates.

As a result of this drying step, the wood boards or veneer are thoroughly dried and held agamstcurling or splitting. After the stock is thus treated and dried it is then confined between heated plates, the stock may be dried by hanging it in a drying roomv after it has been treated by the alkali process, but before the stock has been cut into sepa: rators. In this instance, some of the stock will be wasted because cracks develop at the ends of the stock during the drying step and it is, therefore, necessary to remove the cracked portions from the stock after it is dried and before the separators are out.

We do not intend that our invention shall be limited to any particular type of drying machine but have found that a machine, such as that generally used in the treating of wood veneer, is preferable.

While we do not fully understand the reasons why the separators, when treated,

according to our method, do not curl, we are,

of the opinion, that the cracking, curling and splitting are prevented by the pressure exerted upon the wood during the timethat sulphuric acid to neutralize any caustic soda, they are completely dried and any tendenc to warp, or splitvis removed or neutralize In our opinion, the reason why the boards do not crack objectionably when dried in loo a drying room is that, when this step is to be followed, the stock is cut slightly larger than necessary and because of the complete drying of the boards before the are cut into separatorsthe outer portions 0 the stock act to limit the cracking and curling. It is to be understood when this method is pursued, an allowance must be made for certain waste both at the ends ofthe stock and also on the sides thereof. It is largely 'on this account that we prefer to use means for holding the stock while drying.

Many methods of alkali treatment may be appliedto the separators and a great Varietof machines may be used for drying the stoc without departing from the spirit of our invention.

We claim: 1. The method which consists in treating a separator to remove such of its constituents as would deleteriously attack lead when subjected to electrolytic action and drying the separator between heated surfaces.

2. The method of treating separators which consists in subjecting the separators to a caustic soda treatment and drying them between heated surfaces.

3. The step in the treatment of separators which consists in drying said se arators be.- tween heated surfaces after sai separators have been subjected to the action ofan alkali.

4. The steps in the treatm nt of separators which consists in first subjecting said separators to the action of an alkali and thereafter in drying said separators while held between heated surfaces.

5. The steps in the treatment of separators which consists in first subjecting said separators to the action of an alkaline solution and thereafter in drying said separators be; tween heated surfaces until substantially dry.

,6, The steps in the treatment of separators which consists in first subjecting said separators to the action of an alkali and thereafter in drying said separators between hot metal surfaces.

7. The methodof making separators which consists in treating sheets of wood with an alkali, washing the sheets, drying them between heated surfaces and cutting the se )arators from the sheets.

8. dry flat wood separator that has been treated with an alkali to remove such of its constituents as would be deleterious when used as a battery separator, said separator possessing its natural porosity and strength.

' WILLIAM S. GOULD.

I WILLARD B. OSBORNE. 

